SIDPLAYER NEWS #4  April 1986 

This is the fourth news file for Sidplayer, the music system published in "All 
About The Commodore 64, Volume Two" by COMPUTE! Books.  This news file offers 
many hints, tips, and suggestions on how to more easily create better sounding 
songs.  The information presented here will be of interest to both novices and 
experienced users. 

Please keep in mind that the Sidplayer Editor is to be used only by those who 
have purchased Volume Two.  The Editor is not a Public Domain program.  This 
document is not intended to be a guide on how to use the Editor for people who 
have not purchased the book. 

The main part of this document consists of suggestions organized by command 
name.  After these suggestions you will find some shorter sections that 
describe the symptoms of Master Composer Syndrome, encourage you to hook your 
computer up to a stereo, and offer some advanced techniques to ponder. 

TEM 
1. The Editor lacks a feature to play just a given measure.  Although a fast 
forward feature is available, it can still take a while to skip past part of a 
song.  A faster way to skip over a part is to insert the command TEM 900 at 
the beginning of the part to be skipped, and then insert a TEM command for the 
correct tempo at the place you want to hear.  When you play the song, the part 
to be skipped will be played even faster than is permitted by the fast forward 
feature, and you won't run a risk of getting a CLOBBER error (unless you use 
the fast forward feature as well).  There are two restrictions to the use of 
this technique.  If the part to be skipped contains thirty second notes, tempo 
450 will have to be used instead.  If the part uses utility durations, this 
technique cannot be used. 
2. The tempo chart on page 285 is so handy, it may be worthwhile to photocopy 
the page for quick reference for when you enter a song. 

UTL 
1. If you need to get a portamento glide that is longer than a whole note, you 
can always use the utility duration.  This will permit a glide of any duration 
up to four seconds. 

VOL 
1. It is strongly recommended that you not use volumes above level 12, except 
when you are using the triangle waveform which is naturally quieter.  If you 
use volume levels above 12, especially with the pulse wave, the song may 
overpower the speaker on some televisions, causing the sound to be distorted, 
and thereby detracting from the quality of your song.  Not everybody has their 
C64 hooked up to a nice stereo that can handle the volume. 
2. You need to use the VOL command on only one voice.  The master volume sets 
the volume for all three voices.  If a VOL command is used on more than one 
voice at the same time, the VOL on the highest numbered voice is the one that 
will take effect.  Usually the VOL and BMP commands are used only on voice one. 
3. Be aware that a popping noise occurs when the master volume is changed by 
large amounts.  Some people feel that the popping detracts from the song, and 
try to minimize the popping in their songs.  To reduce the popping, try using 
smaller volume level changes and different positions for the volume changes. 
The sustain levels can also be adjusted to control the overall volume. 

BMP 
1. As with the VOL command, use BMP in only one voice.  If two voices use a 
BMP command at the same time, the volume will be bumped by two levels instead 
of one. 
2. BMP can be used to fade out a song when the last measure or two are 
repeated.  Some songs also use BMP to fade out the last note, but this creates 
a noticeable "stepping" effect in the volume as it changes.  A better way to 
fade out a note is to use a long release (a large RLS value). 

HED and TAL 
1. Remember that repeat loops cannot be nested.  Be especially careful of this 
when you have a repeat loop that contains a phrase call, and the phrase also 
contains a repeat loop. 
2. If at all possible, try to avoid using HED 0 for endless repetition.  A 
song that does not end does not work very well with an autoplayer. 

DEF 
1. Some songs contain several phrase definitions right at the beginning of 
each voice, which often set up waveforms and envelopes that are not used until 
later in the song.  This may be convenient but it is not always a good 
practice.  When Sidplayer has to process several commands before the first 
note, the chance of getting a CLOBBER error is increased.  This error occurs 
when too many commands are placed between notes, and they cannot all be 
processed in one jiffy (one sixtieth of a second).  The intended way for a 
phrase to be used is to define the phrase as it is played the first time, and 
then to call it when it needs to be played again later.  See pages 300 to 304 
for a complete explanation of phrases. 

F-M and FLT 
1. Sometimes it can be handy when editing a song to play only one voice at a 
time.  Unfortunately, this cannot be done if the voice contains a call to a 
phrase defined in a voice that is not being played.  A way to get around this 
limitation is to play the voice that contains the phrase definition but to 
include the commands F-M N and FLT Y at the beginning of the voice.  Selecting 
a filter mode of N (no mode) and passing the voice through the filter makes 
the voice inaudible.  This allows you to play the voice so that the phrase 
gets defined, without hearing the voice itself. 

F-X 
1. In addition to generating tones for music, the SID chip also picks up a lot 
of the "noise" from the circuitry inside the computer.  This undesirable 
background noise can be significantly reduced on some computers by turning on 
the external filter input.  To take advantage of this, just include an F-X Y 
command at the beginning of each song you create.  The songs will be free of a 
lot of the background hiss when played.  Other than making the song sound much 
cleaner, enabling the external filter input will not have any effect on the 
song. 

ATK 
1. It is not always desirable to use a value of 0 for the ATK command.  When 
all three voices have an attack rate of 0, and all three voices start playing 
new notes at the same time, sometimes the SID chip will not gate (start 
playing) the notes together, and one note will noticeably start to sound 
before the others.  The phenomenon is sporadic, but does not occur with slower 
attack rates, so you can use ATK 1 to get around the problem. 

DCY 
1. To minimize the "biting" effect of the volume falling from the attack peak 
to a much lower sustain level, a slower decay rate can be used. 

SUS 
1. Unfortunately, the SID chip does not provide a volume control for each 
voice (the VOL command affects all three voices), but to some extent, the 
sustain level of a voice can be used to control the volume of a voice. 
2. If one voice is playing a melody and other voices are supporting it by 
playing harmony, it is a good idea to have the SUS level for the harmony 
voices set at least one level lower than the sustain level for the melody 
voice.  If they are equal, the harmony voices can overpower the melody voice. 
Setting their SUS levels lower makes the melody voice stand out, and generally 
the song will sound a bit nicer. 

RLS 
1. As with the ATK command, it is a good practice to avoid using the value 0 
with the RLS command.  A release rate of 0 sometimes makes voices cut off 
unevenly.  It is more noticeable when the song is played on a stereo instead 
of a television or monitor speaker.  Values from 1 to 15 are recommended for a 
more pleasant effect. 

PNT 
1. The release point, set by the PNT command, determines the number of jiffies 
from the end of a note that the note should start to release.  Always remember 
that the release point must be less than the duration of the note being 
played, or the note will not be played properly.  For example, in tempo 100 a 
sixteenth note is 9 jiffies long.  If the release point is set to 12, the note 
will start to release as soon as it starts playing.  It will never have a 
chance to complete its attack, and so will not be heard, or will be hardly 
audible.  For this reason the release point is usually set around 4 or 5.  If 
you have the release point set larger and have to play some shorter notes, it 
may be necessary to temporarily set the release point smaller for those notes. 
You can refer to the tempo chart on page 285 to determine the exact jiffy 
count for any note in any tempo. 
2. If notes of longer durations are being played, a reason to use a larger 
release point is to create a more staccato effect. 
3. Setting the release point to 0 means that notes played will never be 
released.  This is the same thing as tying the notes together.  Therefore, if 
you need to enter a lot of notes that are all tied together, for a legato 
effect, set the release point to 0 instead of entering a tie for each note. 
4. If a voice contains alternating notes and rests of the same duration, such 
as a quarter note, quarter rest, quarter note, quarter rest sequence in a bass 
line, a shortcut can be used.  The technique is combine the notes and rests 
into notes of equivalent total duration and then set the release point to make 
the release begin where the rest would normally begin.  For example, let's say 
that the above quarter notes and quarter rests were played in tempo 100, so 
each note and rest was 36 jiffies long, and the release point was set at 4. 
Instead of entering quarter note and quarter rest pairs, you could enter half 
notes and set the release point at 40, where the 40 is 36 jiffies for the 
quarter rest and 4 jiffies for the normal release point of the quarter note. 

WAV 
1. For some reason, pitches played using the pulse wave in octaves 0, 1, and 
some of 2 sound out of tune.  It may be best to avoid using the pulse waveform 
when playing notes in the lowest octaves. 
2. The pulse waveform can be combined with the triangle waveform to create a 
new and useful waveform type.  Just enter the number 5 (4 for pulse plus 1 for 
triangle) to select the WAV TP command.  The resultant waveform is especially 
useful for harpsichord effects. 
3. The waveform combination SP is much quieter and therefore is not as useful. 
All other combinations seem to be inaudible. 
4. Don't put a WAV command right before a rest.  The release of a preceding 
note may continue into a rest, and a waveform change before the rest may clip 
the end of the note and be noticeable.  Instead, just put the WAV command 
right before the next note to be played. 

P-W 
1. Do not use the pulse wave with a pulse width less than 100.  Notes played 
with a width much less than 150 are inaudible on some SID chips. 
2. When using the TP waveform combination, be sure to have the pulse width set 
below 2048.  The volume of the TP waveform decreases as the pulse width goes 
above 2000.  Also set the width below 2048 when using waveform SP. 

P-S 
1. Pulse width sweeping works by adding the pulse sweep value to the pulse 
width once each jiffy.  The only problem with this is that with larger sweep 
rates, the pulse width can exceed 4095, in which case it wraps around and 
starts back at 0.  This causes a very noticeable popping noise which can 
really detract from a song.  To avoid the wraparound you can use a slower 
sweep rate or set the pulse width lower (or higher if you are sweeping 
backwards).  If you want to keep the same pulse width and sweep rate, first 
determine on which notes the wraparound occurs.  These will be the notes with 
the longest durations.  Then take each note which causes popping, divide it 
into two halves tied together, and insert a P-S command between them with the 
same sweep rate but the opposite direction.  For example, if popping occurs on 
a half note when the sweep rate is 30, instead enter a quarter note tied to 
another quarter note of the same pitch, with a P-S -30 command between them. 
You will also need to enter a P-S 30 command after them to reset the direction 
of the sweep for the next note. 

SNC and RNG 
1. Refer to pages 324 to 325 and 333 to 337 of Volume Two for the correct way 
to set up synchronization and ring modulation effects. 

VDP and VRT 
1. For a more natural vibrato effect, you can change the vibrato depth while a 
note is playing.  Just break the note into smaller notes of the same total 
duration, all tied together, and put VDP commands of increasing values between 
them.  Again, remember to reset the depth back to the original value. 
2. Be aware that the vibrato processing is done only for the duration of a 
note, and is not done when a rest is being played.  When a note with a slow 
release rate is followed by a rest, the voice may continue to fade away during 
the first part of the rest.  If vibrato is used on the note, it is sometimes 
noticeable that the vibrato all of a sudden stops as the note is fading away. 
To prevent this from happening, you can delete the rest, add its duration to 
the preceding note, and set the release point higher for that note as 
discussed in the above section on the PNT command. 

TPS 
1. The SID chip cannot play pitches beyond octave 7, even when the TPS command 
is used.  If you try to play a note above B7, the note will be played with the 
same pitch but in octave 7.  Thus an E transposed to octave 8 will be played 
as an E in octave 7.  To determine if a voice is being transposed out of 
range, watch the voice on KPLAY and see if the key goes off the right edge of 
the piano keyboard display and disappears. 
2. It is possible for the SID chip to play pitches in octave -1 by using the 
TPS command with negative values, but this is rarely useful. 

AUX 
1. When using the AUX command to change the color of the piano keys in KPLAY, 
do not use values outside the range of 0 to 15.  Values larger than 15 do not 
give you any new colors, and songs using larger values may forfeit 
compatibility with future editions of players. 

MISCELLANEOUS 
1. Be very careful to never let two voices using the same waveform play notes 
of the exact same pitch at the very same time.  When this is allowed to 
happen, a phenomenon known as "destructive harmonic interference" can occur, 
which in no way damages your computer but can cause the two voices to cancel 
each other out and be inaudible.  The effect happens randomly and is not 
always noticeable.  The only time that two voices should simultaneously play 
the exact same pitches in the same octave with the same waveform is when the 
voices are being detuned. 
2. If two notes of the same pitch are tied together, it is a good practice to 
put the shorter note first.  This is because a note tied to another note does 
not release.  If the longer note is put first, the release cannot begin until 
the shorter note starts playing, and in some cases the release would normally 
begin sooner.  This is especially true when larger release points are used. 
Putting the shorter note before the longer note ensures that the release will 
begin at the appropriate place. 
3. When a grace note is played, remember that the duration for the grace note 
should come out of the duration for the preceding note.  This way, the note 
following the grace note will begin right on the beat, as it should, instead 
of the grace note.  It may be necessary to use utility durations for both the 
grace note and the note preceding it. 
4. KPLAY and MPLAY and the other players end a song right when the last 
duration is complete, even if some of the voices are not done releasing.  To 
let each voice fade out and finish completely, it is a nice touch to put a 
rest after the last note in each voice. 
5. Remember that when you are creating a very long song, it is much easier to 
break the song into parts, enter and edit each part separately, and then 
combine them using the MERGE utility found on page 369.  This utility can also 
be used to create songs larger than what the Editor can hold in memory. 
6. The LISTER utility on page 365, or the revised version called PRINTER which 
prints in three columns only to a printer, can be used to find duration bugs 
in songs.  See SIDNEWS#1 for information on the PRINTER utility. 
7. Whenever possible, please try not to use the default waveform and envelope. 
The default settings were chosen because they give a simple, neutral waveform 
and envelope which can be modified easily.  Playing all three voices with the 
default square wave and organ-type envelope, however, can make any song, even 
a very good one, sound pretty blah. 
8. Don't overlook the subtle but significant effects that different envelope 
settings can have on a song.  Envelopes seem to be one of the most ignored 
aspects of songs. 

MASTER COMPOSER SYNDROME 
It has been observed that people who formerly used the Master Composer music 
system and now use Sidplayer exhibit a strong tendency to use a heavy dose of 
vibrato and pulse width sweeping in their songs.  Presumably this is because 
these are two easy-to-use features that are not found on Master Composer.  If 
you might be such a person, we urge you to control your fascination with these 
features and use them sparingly.  Thank you! 

THE BASEBALL CARD PHENOMENON 
Some music systems may make songs sound better than other music systems, but 
the quality of a song depends just as much, if not more so, on the time and 
care taken by the person entering the song.  While it is nice to have lots of 
songs to collect and trade, it is also important to keep the quality level 
high in order to maintain interest in the songs.  We would prefer to encourage 
people to emphasize quality over quantity. 

SIDPLAYER ON YOUR STEREO 
If you don't have your computer hooked up to a stereo, you're only getting 
part of the story when you play a song.  Playing songs over a stereo gives you 
fuller bass lines and triangle waveforms, and reveals other things you never 
knew were there.  See SIDNEWS#1 for instructions on how to hook your computer 
up to a stereo. 

SOME ADVANCED TECHNIQUES TO PONDER 
1. The sync mode is not used very often because it requires two voices, 
leaving only one voice free.  The mode offers a whole variety of new tone 
types, however, and is definitely worth investigating.  Try the sync mode with 
different combinations of waveforms and TPS values, as demonstrated by the 
song TPI#14. 
2. See page 337 for a discussion of using sync and ring modulation at the same 
time.  With this technique, you can sometimes get tones that sound like they 
are being filtered, even though they are not. 
3. Another possibility is to use portamento with the sync mode.  This is done 
by putting an absolute set command of a different pitch before each note that 
is played.  When this is done on the synchronized voice which adds the 
harmonics, an interesting "wah" effect is produced, as in the song ETAL. 
4. Some people have gotten interesting results by using the sync or ring 
modulation modes with nonstandard configurations. 
5. Absolute set commands can be placed between rests following a note with a 
large RLS value to make a note slowly fade away while changing pitch.  This 
technique was used in the song STUNTMAN. 
6. A subtle technique is to use the absolute set command with detuning and 
portamento.  Turn on the detuning and set a detuned pitch with the absolute 
set command.  Then turn off the detuning and play a note with a slow 
portamento rate in effect.  The note will not start at exactly the correct 
pitch but will move to the desired pitch.  This may be useful for simulating 
some vocal effects.  A variation on this method is to not use detuning and 
just use the absolute set command to set the pitch one half step below the 
desired pitch, with a faster portamento rate. 
7. Detuning and transposition can be an interesting combination.  Octave 
transpositions with detuning were used in PIPERS, CALLIOPE, BISTRO, and 
AMERICA. 
8. An advanced use of detuning is to slightly detune a voice, even when it is 
not being played along with another voice containing the same notes, for a 
fuller sound.  This technique is based on a principle used by barbershop 
quartets. 
9. The POLYCON utility can be used to add a pedal effect or lingering effect 
(like a bell) to a song, as in FUER.  This technique can also be used with 
fast arpeggios for another interesting effect.  See SIDNEWS#3 for full 
instructions. 
10. Detuning with polyphony also gives an interesting effect.  This 
combination was used in the song ISLAND. 
11. When the waveform TP is used, pulse width sweeping can be used to sweep 
the width past 2048, thereby making the volume fade out. 
12. A note by note use of utility duration is very tedious but can produce 
some wonderful phrasing effects.  See the song FUER for an example.  Even 
using just a few carefully placed utility durations can add a nice, more 
natural touch to a song. 
13. When two voices are playing similar notes, perhaps with different pulse 
widths or detuning, a very short utility duration rest can be placed at the 
beginning of one of the voices to create an echo effect.  See the version of 
TAKE FIVE by Stan Halaby for an example. 
14. While having only three voices can be quite a limitation, it is sometimes 
possible to use one voice for two different effects simultaneously.  For 
example, CANTINA uses the same voice for both bass notes and percussion 
effects.  The bass notes are played on the beat and the percussion effects are 
played on the offbeat.  Phrase calls can make it easy to alternate between 
different waveform and envelope settings. 
15. One technique to get around volume problems on a voice is to release a 
note before has completed its attack phase.  This will require some 
experimentation with attack rates and release points.  The technique was used 
in the stereo version of AXEL F. 
16. A rapid succession of different pitches using white noise makes an 
interesting percussion line, as in the song IBEX. 
17. Longer white noise notes, as in the song OSPREY, can also give an 
interesting effect. 
18. One other interesting effect is to play a sequence of notes of the same 
pitch but with different pulse widths. 

FINAL REMARKS 
1. Some of these suggestions and techniques are described in the book, along 
with complete instructions on how to use the Sidplayer Editor and a fairly 
comprehensive introduction to music theory. 
2. Most people feel that it is worth $16.95 to get the complete documentation. 
3. Other music systems cost twice as much and are not as well documented. 
4. The book also has bitmapped graphics and sprite utilities, and sections on 
Advanced BASIC. 
5. The Sidplayer Editor is not a Public Domain program and is supposed to be 
used only by those who have purchased Volume Two. 

If you use the Sidplayer Editor and don't have the book... 